Dr John Roche: Comparative stocking rate

Published 21 January 14

As we move towards the 2014 grazing season, now is a good time to consider how we can maximise efficiency in our grazing systems. Balancing stocking rate against pasture growth potential is essential to ensure maximum profitability. In this video grassland expert Dr John Roche from Down to Earth Advice explains how comparative stocking rate can be a useful metric for grassland managers. 

“Profit response to stocking rate is not linear” says John, “optimum response will depend on a number of factors including your pasture growth potential, the size of the cow you are milking , concentrates fed and other non-milking stock”. As a result it can be difficult to compare and use stocking rate effectively as a metric on farm.

Researchers in New Zealand have introduced the concept of comparative stocking rate as a metric for helping assess profitability on farm. Comparative stocking rate takes account of both differences in location (grass growth potential) and system (concentrate feeding rate).

It is a balance between pasture utilisation and cow production and there is an optimum stocking rate for profit depending on cow size and feed availability. Researchers in New Zealand have calculated that for 5000-7500lt herds this to be 77kg liveweight per tonne of feed dry matter available.

Comparative stocking rate calculation: DairyCo examples

Cows (no.)

100

Average cow weight (kg)

550

Total liveweight (kg)

55000

 

 

Grass growth (t DM/ha)

14

Grazing platform (ha)

50             

Total herbage production (t DM)

700

 

 

Stocking Rate on Pasture (cows/ha)

2.0

Comparative stocking Rate (kg LW/t DM)

78.6

Outcome: No bought in feed required

 

 

 

 

 

 

 

 

 

 

Cows (no.)

100

Average cow weight (kg)

550

Total liveweight (kg)

55000

 

 

Grass growth (t DM/ha)

11

Grazing platform (ha)

50             

Total herbage production (t DM)

550

 

 

Stocking Rate on Pasture (cows/ha)

2.0

Comparative stocking Rate (kg LW/t DM)

100

Outcome: Additional feed required at 1.5 tDM/cow